The demand for data storage protection and capacity in computer networking environments increases substantially each year. Internet use and data-intensive applications, such as multimedia and online transaction processes, have contributed to the increased demand for data storage capacity. Users are also demanding faster access to the data and the ability to share pooled data among a large number of users over distributed locations. In addition to these demands, many network administrators desire the ability to efficiently change the amount of storage available on a network and provide maintenance to the existing storage.
Today, the computer industry is turning to storage area networks (SANs) to meet demands for increased storage capacity and more rapid access to data. A conventional SAN typically includes a collection of data storage devices interfaced with one or more servers or workstations. Many SANs use Fibre Channel (FC) technology in order to transmit data at higher rates. FC devices are generally based on Fibre Channel Protocol (FCP), which may support multiple protocols including Small Computer Serial Interface (SCSI), Asynchronous Transfer Mode (ATM), Transmission Control Protocol/Internet Protocol (TCP/IP), High Performance Parallel Interface (HiPPI), Intelligent Peripheral Interface (IPI) and others.
In the event that a storage device containing a server boot partition fails, a system administrator must manually bring the server back online. In order for the system administrator to restore the data from the failed storage device, the system administrator first must be notified of the failure. The system administrator must then determine which storage device failed and locate a spare storage device on the network. Finally, the system administrator must manually restore the data to the spare storage device by using the backup data from the failed storage device and assign the spare storage device to the server so that the server has access to the restored data. The process is not only time consuming for the system administrator but can waste time for users on the network since the system administrator may not be able to correct the problem immediately after the failure occurs.
To eliminate the manual restoration process, data partitions in a SAN may be mirrored. The mirroring technique requires that each host on the network store data on a primary storage device and a backup storage device. Mirroring, therefore, requires twice the number of storage devices than a SAN without mirroring. Furthermore, since the host must store data in at least two storage devices, the speed of the network may be effected.